Iron deficiency shows up in the parts of the plant that are closest to the light- so don't lower them yet, but I have my 600s 12 inches away from the plants average, as I have for six or more years. It's totally fine to have them that close. Mine are not air cooled lights just bare bulbs, new Hortilux.
Your results might vary- but in my experience those bulbs don't burn plants till they're closer than 8" or so.
Pretty sure I said this stuff on this thread already come to think of it...
As long as there are movement fans blowing air underneath the bulbs so that you don't get hotspots it shouldn't be a problem
Your results might vary- but in my experience those bulbs don't burn plants till they're closer than 8" or so.
Pretty sure I said this stuff on this thread already come to think of it...
As long as there are movement fans blowing air underneath the bulbs so that you don't get hotspots it shouldn't be a problem
